I agree with the Resident Evil 1 bit. Played that when I was really young, and the moment the zombie turned around I ran out of the room (as in the real room I was playing the game in). I refused to go back in until I got someone to turn the PS1 off.

In the fps Blood 2, there were enemies that were like crossbreeds of leeches and beetles, and they would attack by launching themselves onto your face and making the screen black. Those really scared me.

Vivisector is nowhere near as deep as Cryostasis, but for good reason. It's a fucking awesome horde shooter. There are some very atmospheric parts though. The story is silly but the writing is... poetic. Not good or realistic, but poetic.